| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 127 |
| 5 | 1321 |
| 6 | 16680 |
| 7 | 244518 |
| 8 | 4049199 |
| 9 | 74404069 |
| 10 | 1498276873 |
| 11 | 32764372213 |
| 12 | 772675039936 |
| 13 | 19541627299052 |
| 14 | 527590805816280 |
| 15 | 15146369004674536 |
| 16 | 460804123171138079 |
| 17 | 14811876349937896743 |
| 18 | 501663013214822053815 |
| 19 | 17858867621856721343253 |
| 20 | 666744417234185576463077 |
[1,1,3,16,127,1321,16680,244518,4049199,74404069, 1498276873,32764372213,772675039936, 19541627299052,527590805816280,15146369004674536, 460804123171138079,14811876349937896743, 501663013214822053815,17858867621856721343253, 666744417234185576463077] |